He was remote, but not quite that remote. At least in his mind, he knew he always had to fear getting caught and be as camouflaged as possible. Heck, he didn't even allow himself a fire.

These sort of constraints make some of the primitive technology quite a bit more difficult to utilize.

Not to mention that he was relying on stealing books - the folks he was stealing from needed to be interested in such things. In their (assumingly) middle class homes, I can see how that might not be in their libraries.